CN109508028A - A kind of attitude of flight vehicle disturbance filtering method, apparatus and system - Google Patents

Abstract

The invention discloses a method, a device and a system for filtering attitude disturbance of an aircraft caused by flapping motion. A motion capture system collects motion signals of a flapping aircraft, an aircraft control system collects attitude signals, and a host computer respectively analyzes signal characteristics to obtain corresponding frequency spectrums. Figure, determine the aircraft flapping motion as the source of attitude disturbance; the motion capture system collects the motion signal corresponding to the flapping aircraft when the throttle signal gradually increases, and the upper computer analyzes the signal characteristics of it, and performs the throttle and flapping frequency fitting; According to the fitting relationship between the throttle and the flapping frequency, the aircraft obtains the flapping frequency corresponding to the maximum throttle signal, and uses it as the frequency threshold to perform a low-pass filter to filter out high-frequency interference signals; The frequency spectrum is analyzed by filtering the signal, and according to the amplitude threshold, the main frequency is screened out as the frequency of the disturbance signal, and the band-stop filter is performed to filter out the disturbance signal of the flapping-wing aircraft.

Description

A method, device and system for filtering attitude disturbance of aircraft

technical field

The invention belongs to the technical field of aircraft control, and relates to a method, device and system for filtering attitude disturbance of an aircraft, in particular to a method, device and system for filtering attitude disturbance of an aircraft caused by flapping wing motion.

Background technique

Small unmanned aerial vehicles have attracted widespread attention from the very beginning because of their small size, light weight, easy portability, convenient operation, flexible maneuverability, small take-off and landing space, low noise, and good concealment. It is one of the high-tech products with broad development prospects. According to the different lift generation and propulsion mechanisms, small unmanned aerial vehicles can be divided into: fixed wing, rotor and flapping wing. The flight mechanism of fixed-wing and rotary-wing small unmanned aerial vehicles is the same as that of traditional fixed-wing aircraft and helicopters, respectively. There is still some theoretical knowledge and field data for their development work for reference. The flapping-wing bionic aircraft is a new type of aircraft that imitates the flight of birds or insects. The lift and thrust required for its flight are all generated by the flapping motion, and the flight principle is completely different from the previous two.

Compared with conventional aircraft, the aerodynamic characteristics of small unmanned aerial vehicles are very different, and their Reynolds coefficient is relatively low (Reynolds coefficient represents the ratio of air inertial force and viscous force, and the Reynolds coefficient of conventional aircraft is between 10 ⁶ and 10 ⁸ ). between 10 ¹ and 10 ⁵ of small unmanned aerial vehicles). Under such a low Reynolds coefficient, no flying creatures in nature, such as birds and insects, use fixed-wing or rotary-wing flight, but all use flapping wings to fly. The flapping-wing aircraft has the following advantages: the flapping-wing aircraft has stronger maneuverability and flexibility, and the flapping-wing flight only relies on the flapping and twisting of the wings to achieve changes in body position and attitude, while the fixed-wing and rotary-wing aircraft require multiple powers In the process of flight, flapping-wing flight can fly by gliding, which saves a lot of energy compared with fixed-wing and rotary-wing aircraft; at the same time, flapping-wing flight has high energy conversion efficiency, and uses less energy. Achieving a long flight distance is very suitable for performing long-distance tasks; flying creatures in nature all choose flapping flight, which also shows that flapping flight is more advantageous to a certain extent.

Although domestic and foreign research institutions have made a series of achievements in the development of flapping-wing aircraft, which enable the flapping-wing aircraft to fly, the stable flight of the flapping-wing aircraft is still an urgent problem to be solved. The stable flight of the flapping-wing aircraft is inseparable from precise attitude control. Therefore, it is extremely important to accurately measure the change of the aircraft attitude and filter out the attitude disturbance for the stable flight of the aircraft. During the flight of a flapping-wing aircraft, lift is obtained by the continuous flapping of the wings, which can overcome gravity to achieve flight. However, due to the periodic inertial force, the up and down flapping motion of the wings will inevitably cause the aircraft to move in the pitch direction. The regular up and down movement will cause great disturbance to the true pitch angle of the aircraft, so that it presents the characteristics of periodic signal changes. Precise control makes the aircraft unable to fly stably. Therefore, it is necessary to solve the attitude disturbance caused by the flapping motion.

To sum up, there is still no effective solution for how to solve the problem of attitude disturbance caused by flapping wing motion in the prior art.

SUMMARY OF THE INVENTION

Aiming at the deficiencies in the prior art and solving the problem of the attitude disturbance caused by the flapping motion in the prior art, the present invention provides a method, device and system for filtering the attitude disturbance of the aircraft caused by the flapping motion, especially a A method, device and system for filtering the attitude disturbance of an aircraft caused by flapping motion, which can accurately capture the disturbance frequency of the flapping motion of the flapping aircraft to the true attitude angle of the aircraft, and use the disturbance frequency to follow the adaptive filter to effectively realize the filtering The aircraft attitude disturbance caused by flapping motion enables the aircraft control system to precisely control the aircraft attitude.

The first object of the present invention is to provide a method for filtering out the attitude disturbance of an aircraft caused by flapping motion.

In order to achieve the above object, the present invention adopts the following technical scheme:

A method for filtering out the attitude disturbance of an aircraft caused by flapping motion, the specific steps of the method include:

The motion capture system collects the motion signals of the flapping-wing aircraft, the sensors in the aircraft control system collect the attitude signals, and upload them to the corresponding host computer respectively. Determine the flapping motion of the aircraft as the source of attitude disturbance;

The throttle motion capture system of the graded fixed flapping aircraft collects the corresponding motion signals of the flapping aircraft when the throttle signal gradually increases and uploads it to the upper computer. Fitting of flapping frequencies;

The upper computer obtains the flapping frequency corresponding to the maximum throttle signal according to the fitting relationship between the throttle and flapping frequency, and uses it as the frequency threshold to design an analog low-pass filter, which is converted into a digital low-pass filter and set in the aircraft control system to filter out flapping flaps. High-frequency interference signals of wing aircraft;

The host computer performs spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal. According to the amplitude threshold, the main frequency is screened out as the frequency of the disturbance signal. Filter out the disturbance signal of the flapping aircraft.

As a further preferred solution, in this method, the aircraft control system stores the collected attitude signals and throttle signals in the form of logs, and the host computer reads the attitude signals and throttle signals in the logs.

As a further preferred solution, in this method, the upper computer uses FFT transformation to respectively analyze the signal characteristics of the motion signal and the attitude signal to obtain the corresponding spectrogram.

As a further preferred solution, in this method, the analog low-pass filter is transformed into a digital low-pass filter by a bilinear transformation method.

As a further preferred solution, in this method, the analog band-stop filter is transformed into a digital band-stop filter by a bilinear transformation method.

As a further preferred solution, in this method, the method for screening out the main frequencies also includes:

The low-pass filtered signal after filtering out the high-frequency interference signal is sampled with a specific length, and the layered retention method is used for zero-filling, FFT transformation is performed, and the main frequency is filtered out according to the amplitude threshold.

The second object of the present invention is to provide a system for filtering the attitude disturbance of the aircraft caused by flapping motion.

In order to achieve the above object, the present invention adopts the following technical scheme:

A system for filtering the attitude disturbance of an aircraft caused by flapping motion, the system comprising:

The motion capture system is used to collect the motion signal of the flapping aircraft and upload it to the upper computer;

The upper computer is used to receive the collected motion signals and attitude signals of the flapping aircraft, analyze the signal characteristics of them respectively to obtain the corresponding spectrograms, and determine the flapping motion of the aircraft as the source of attitude disturbance by comparing the spectrograms; receive the throttle signals and flapping wings. The motion signal of the aircraft when the throttle signal is gradually increased, the signal characteristics are analyzed, and the throttle and flapping frequencies are fitted; according to the fitting relationship between the throttle and the flapping frequency, the flapping frequency corresponding to the maximum throttle signal is obtained, Use it as a frequency threshold to design an analog low-pass filter to filter out high-frequency interference signals; perform spectrum analysis on the low-pass filtered signal after filtering out high-frequency interference signals, and filter out the main frequencies as the disturbance signal frequency design simulation according to the amplitude threshold Band-stop filter to filter out disturbance signals;

A flapping-wing aircraft control system, the hardware part mainly includes controllers and sensors, and the software part mainly includes digital low-pass filters and digital band-stop filters, etc., which are used to control the flight of the flapping-wing aircraft. The sensors are used to collect attitude signals and Uploaded to the host computer, the digital low-pass filter is transformed according to the analog low-pass filter designed by the host computer to filter out high-frequency interference signals; The digital band-stop filter is transformed according to the analog band-stop filter designed by the host computer. Obtained to filter out the disturbance signal of the flapping aircraft.

The third object of the present invention is to provide a method for filtering the attitude disturbance of the aircraft caused by flapping motion.

In order to achieve the above object, the present invention adopts the following technical scheme:

A method for filtering out the attitude disturbance of an aircraft caused by flapping motion, the method is implemented in a host computer, and the specific steps include:

Receive the collected motion signal and attitude signal of the flapping-wing aircraft, analyze the signal characteristics of them respectively to obtain the corresponding spectrogram, and determine that the flapping-wing motion of the aircraft is the source of attitude disturbance by comparing the spectrograms;

Receive the throttle signal and the corresponding motion signal of the flapping aircraft when the throttle signal gradually increases, analyze the signal characteristics, and perform the fitting of the throttle and flapping frequencies;

According to the fitting relationship between the throttle and the flapping frequency, the flapping frequency corresponding to the maximum throttle signal is obtained, and it is used as the frequency threshold for low-pass filtering to filter out high-frequency interference signals;

Perform spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal. According to the amplitude threshold, screen out the main frequency as the frequency of the disturbance signal and perform band-stop filtering to filter out the disturbance signal.

A fourth object of the present invention is to provide a computer-readable storage medium.

In order to achieve the above object, the present invention adopts the following technical scheme:

A computer-readable storage medium in which a plurality of instructions are stored, and the instructions are adapted to be loaded by a processor of a terminal device and perform the following processes:

Receive the collected motion signal and attitude signal of the flapping-wing aircraft, analyze the signal characteristics of them respectively to obtain the corresponding spectrogram, and determine that the flapping-wing motion of the aircraft is the source of attitude disturbance by comparing the spectrograms;

Receive the throttle signal and the corresponding motion signal of the flapping aircraft when the throttle signal gradually increases, analyze the signal characteristics, and perform the fitting of the throttle and flapping frequencies;

According to the fitting relationship between the throttle and the flapping frequency, the flapping frequency corresponding to the maximum throttle signal is obtained, and it is used as the frequency threshold for low-pass filtering to filter out high-frequency interference signals;

Perform spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal. According to the amplitude threshold, screen out the main frequency as the frequency of the disturbance signal and perform band-stop filtering to filter out the disturbance signal.

A fifth object of the present invention is to provide a terminal device.

In order to achieve the above object, the present invention adopts the following technical scheme:

A terminal device includes a processor and a computer-readable storage medium, where the processor is used to implement various instructions; the computer-readable storage medium is used to store a plurality of instructions, the instructions are suitable for being loaded by the processor and performing the following processing:

Receive the collected motion signal and attitude signal of the flapping-wing aircraft, analyze the signal characteristics of them respectively to obtain the corresponding spectrogram, and determine that the flapping-wing motion of the aircraft is the source of attitude disturbance by comparing the spectrograms;

Receive the throttle signal and the corresponding motion signal of the flapping aircraft when the throttle signal gradually increases, analyze the signal characteristics, and perform the fitting of the throttle and flapping frequencies;

According to the fitting relationship between the throttle and the flapping frequency, the flapping frequency corresponding to the maximum throttle signal is obtained, and it is used as the frequency threshold for low-pass filtering to filter out high-frequency interference signals;

Perform spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal. According to the amplitude threshold, screen out the main frequency as the frequency of the disturbance signal and perform band-stop filtering to filter out the disturbance signal.

Beneficial effects of the present invention:

The method, device and system for filtering the attitude disturbance of the aircraft caused by the flapping motion of the present invention can accurately capture the disturbance frequency of the aircraft's true attitude caused by the flapping motion of the flapping aircraft, and can effectively filter the attitude disturbance signal, The aircraft control system can precisely control the attitude of the aircraft.

Description of drawings

The accompanying drawings that form a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute improper limitations on the present application.

Fig. 1 is the flow chart of the method for filtering out the attitude disturbance of the aircraft caused by the flapping motion of the embodiment 1 of the present invention;

2 is a flowchart of a digital low-pass filtering method according to Embodiment 1 of the present invention;

3 is a flowchart of a method for obtaining a disturbance frequency according to Embodiment 1 of the present invention;

4 is a flowchart of a band-stop filtering method according to Embodiment 1 of the present invention;

5 is a diagram of a mid-fuselage disturbance signal and a frequency spectrum thereof according to Embodiment 1 of the present invention;

6 is a diagram of a pitch angle sampling signal diagram of the mid-flight control system according to Embodiment 1 of the present invention and a spectrum diagram thereof;

7 is a low-pass filtering diagram of the pitch angle sampling signal of the mid-flight control system according to Embodiment 1 of the present invention and a spectrum diagram thereof;

FIG. 8 is a band-stop filtering diagram and a spectrum diagram of the pitch angle low-pass filtering signal of the mid-flight control system according to Embodiment 1 of the present invention;

FIG. 9 is a flowchart of a method for filtering out attitude disturbance of an aircraft caused by flapping motion according to Embodiment 2 of the present invention.

Detailed ways:

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the application. Unless otherwise specified, all technical and scientific terms used in the examples have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

It is noted that the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of methods and systems according to various embodiments of the present disclosure. It should be noted that each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which may include one or more components used in implementing various embodiments Executable instructions for the specified logical function. It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It should also be noted that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented using dedicated hardware-based systems that perform the specified functions or operations , or can be implemented using a combination of dedicated hardware and computer instructions.

In the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be further described below with reference to the accompanying drawings and embodiments.

Example 1:

The purpose of this embodiment 1 is to provide a method for filtering out the attitude disturbance of the aircraft caused by flapping motion.

In order to achieve the above object, the present invention adopts the following technical scheme:

As shown in Figure 1,

A method for filtering out the attitude disturbance of an aircraft caused by flapping motion, the specific steps of the method include:

Step (1): the motion capture system collects the motion signal of the flapping aircraft, the sensor in the aircraft control system collects the attitude signal, and uploads it to the corresponding host computer respectively, and the host computer performs signal feature analysis on the motion signal and the attitude signal to obtain the corresponding frequency spectrum. Figure, by comparing the spectrogram, it is determined that the aircraft flapping motion is the source of attitude disturbance;

Step (2): The grading fixed flapper throttle motion capture system collects the motion signal corresponding to the flapper when the throttle signal gradually increases and uploads it to the upper computer. The throttle data is used to fit the throttle and flapping frequency;

Step (3): The upper computer obtains the flapping frequency corresponding to the maximum throttle signal according to the fitting relationship between the throttle and the flapping frequency, and uses it as the frequency threshold to design an analog low-pass filter, which is converted into a digital low-pass filter and set in the aircraft control. Filter out high-frequency interference signals of flapping-wing aircraft in the system;

Step (4): the host computer performs spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal, and selects the main frequency as the disturbance signal frequency according to the amplitude threshold, designs an analog band-stop filter, and converts it into a digital band-stop filter. It is set in the aircraft control system to filter out the disturbance signal of the flapping aircraft.

Step (1) Disturbance signal analysis:

Step (1-1): Collect data. Install several reflective balls on the fuselage and both ends of the wings of the flapping-wing aircraft to make the flapping-wing aircraft perform flapping motion, collect the spatial motion signals of the aircraft through the optical three-dimensional motion capture system, and output data through the corresponding host computer; the aircraft control system , such as an embedded processing board, installed on the flapping aircraft, following the movement of the flapping aircraft, obtaining external motion information and sampling the attitude signal through the onboard IMU sensor, and the measured attitude signal of the aircraft is stored in the SD card in the form of logs , the data in the log is read by the ground station of the aircraft, that is, the upper computer.

In step (1-1) of this embodiment, the aircraft control system stores the collected attitude signal in the form of a log, and the upper computer reads the attitude signal in the log.

Step (1-2): Data analysis. The host computer analyzes the signal characteristics of the motion signal and the attitude signal respectively, and performs FFT changes on the two parts of the data respectively to obtain the corresponding spectrogram. By comparing the spectrogram, it is determined that the aircraft flapping motion is the source of the attitude disturbance. Figure 5 shows the fuselage disturbance signal diagram and its frequency spectrum. Figure 6 shows the pitch angle sampling signal diagram of the flight control system and its frequency spectrum.

Step (2) flapping frequency analysis:

Step (2-1): Collect data. The throttle of the flapping aircraft is fixed in stages, and the motion signal of the flapping aircraft when the throttle signal is gradually increased is captured by the optical 3D motion capture system. Capture the aircraft motion signal of the system for analysis.

Step (2-2): data fitting. The upper computer analyzes the signal characteristics of the motion signal, performs the FFT change to obtain the main frequency, reads the throttle data in the log of the flapping aircraft, and uses the polynomial fitting method to fit the throttle and the flapping frequency;

In step (2-2) of this embodiment, the aircraft control system stores the collected throttle signal in the form of a log, and the upper computer reads the throttle signal in the log.

Step (3) high-frequency interference signal filtering: in the present embodiment, the analog filter design method is used to design a normalized analog low-pass filter, and then the bilinear transformation method (BLT) of the analog filter to digital filter is utilized. ) to obtain a digital filter, and finally use the digital low-pass filtering method to obtain the difference equation, and iteratively obtain the filtered signal, thereby filtering out the high-frequency interference signal.

Step (3-1): Design an analog low-pass filter. The upper computer obtains the flapping frequency corresponding to the maximum throttle signal according to the fitting relationship between the throttle and the flapping frequency, and uses it as the frequency threshold to design an analog low-pass filter.

As shown in Figure 2, a normalized analog low-pass filter, that is, a prototype low-pass filter, is first designed. The indicators are as follows: pass-band boundary frequency f _pass , stop-band boundary frequency f _stop , pass-band fluctuation R _p and stop-band fluctuation R _s , according to the above indexes, the cut-off frequency is f _c and the filter order L _{n is} obtained, and the normalized analog low-pass filter system function is obtained; And the low-pass filter system function is obtained, and then the difference equation is obtained; finally, the attitude angle signal of the aircraft is sampled at the sampling frequency of F _s , the sampling sequence length is L, and the sampling signal is low-pass filtered. The pass filtered signal output is:

which is,

Among them, the x(n) sequence is the signal sequence before filtering, a _k and b _m are the systematic arrays of the denominator and numerator of the low-pass filter system function, N and M are the length of the systematic array of the denominator and numerator of the system function, respectively, y (n) is the filtered signal sequence, and the x(n) and y(n) sequences are equal, a ₀ =1, when k<0, both x(k) and y(k) are 0. After iteration, all values of the y(n) sequence can be found.

Figure 7 shows the low-pass filtering diagram of the pitch angle sampling signal of the flight control system and its frequency spectrum.

Step (3-2): implement high-frequency interference signal filtering on the aircraft control system. The above-mentioned analog filter is transformed into a digital low-pass filter by the Bilinear Transform (BLT) method. This step is implemented on the aircraft control system.

Step (4) Disturbance signal filtering:

Step (4-1): The host computer performs spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal, and performs FFT transformation. During the FFT transformation, the disturbance frequency capture accuracy and signal processing low delay are ensured. According to the amplitude threshold, filter out The main frequency, namely the disturbance frequency acquisition;

As shown in Figure 3, the method of screening out the main frequencies, that is, the acquisition of the disturbance frequency, also includes:

The low-pass filtered signal after filtering out the high-frequency interference signal is sampled with a specific length. In order to solve the delay problem, the layered retention method is used for zero-filling, which also meets the requirements of resolution, and FFT transformation is performed. frequency.

In this embodiment, the layered retention method is used to solve the data delay problem, and at the same time, frequency domain analysis methods including discrete Hartley transform (DHT), discrete W transform (DWT), and DFT can be used, and then discrete Fourier transform is used in this application example. The Fast Algorithm of Leaf Transform The Fast Fourier Transform (FFT) analyzes the frequency characteristics of the signal. However, the above methods are only some application examples of this method, but not all application examples.

First, for formula (2), divide it into the jth block data y _j (n) of length L, and perform FFT transformation of L point on the block data, and transform it into the frequency domain, then the y point of L point _{The j} (n) signal transformation can be written as:

in, but Independent of y _j (n), i and n represent matrices, respectively The row and column labels of ; Y _j (i) represents the transformed value of the y _j (n) sequence in the frequency domain, which is a complex sequence of L points, and each point corresponds to a frequency point. According to the center symmetry of the FFT transformation, there are L /2+1 points of useful information, repeated information is usually not displayed in the signal spectrum; then for the transformation result of formula (3), obtain the amplitude characteristic A _{n corresponding to each frequency point F n ;} finally set according to the signal characteristics Amplitude threshold A _c , filter out disturbance frequency F _c :

F _n =(i-1)F _s /L,1≤i<L/2+1 (4)

A _n =|Y(i)|,1≤i<L/2+1 (5)

When i=1, i.e. 0hz, the first point represents the DC component

When i≠1, take

F _c ={F _n |A _n >A _c ,1≤n<L/2+1} (6)

Thereby, the disturbance frequency in the block data is obtained.

However, each time a sequence y _j (n) of length L is acquired to perform FFT transformation of point L, a delay of point L-1 will be generated, which is not allowed for the aircraft control system with high real-time requirements. Therefore, this unit applies For example, the data was collected using the overlap retention method. Assuming that the number of updated data in each calculation is L _New , the L point block data participating in the FFT transformation each time is the tail data of LL _New previous block data and L _New new sampling data, then:

when j=0

When j=1,2,3...

In this embodiment, a normalized analog band-stop filter is first designed by using an analog filter design method, and then the analog filter is converted by a bilinear transformation (BLT) method of converting an analog filter to a digital filter, and finally the analog filter is converted. Using the digital band-stop filtering method, the difference equation is obtained, and the filtered signal is iteratively obtained to filter out the disturbance signal.

Step (4-2): Design an analog bandstop filter. An analog band-stop filter is designed by taking the selected main frequency as the frequency of the disturbance signal, which is converted into a digital band-stop filter and set in the aircraft control system to filter out the disturbance signal of the flapping-wing aircraft.

In this embodiment, the disturbance signal is filtered in real time. In the case of low delay, the frequency of the disturbance signal is followed to determine the corresponding filter index, and a band-stop filter is designed to filter out the disturbance signal by using the digital filtering method.

As shown in Figure 4, first, according to the perturbation frequency obtained by equation (6), design the upper and lower limit frequencies f _pU and f _pL of the band-stop filter, the upper and lower limit frequencies of the stop band f _sU , f _sL , and the fluctuation of the pass band is R _pband , the stop band fluctuation R _sband , and then according to the above indicators, the upper and lower cut-off frequencies f _cU , f _cL of the stop band and the order L _N of the band stop filter are obtained, and then the normalized analog band stop filter is obtained. Then the digital band-stop filter is obtained by the bilinear transformation method, and the system function of the digital band-stop filter is obtained, and then the filtering difference equation is obtained. The method of (1) and (2) is used to iterate Find the final filtered signal. Figure 8 shows the band-stop filter diagram and its spectrum diagram of the pitch angle low-pass filter signal of the flight control system.

Step (4-3): implement disturbance signal filtering on the aircraft control system. The above-mentioned analog band-stop filter is transformed into a digital band-stop filter by the Bilinear Transform (BLT) method. This step is implemented on the aircraft control system. Ensure that the aircraft can fly stably according to the desired attitude angle, so as to avoid unexpected situations of the aircraft due to large attitude disturbances.

The purpose of this embodiment also includes providing a system for filtering the attitude disturbance of the aircraft caused by flapping motion.

In order to achieve the above object, the present invention adopts the following technical scheme:

A system for filtering the attitude disturbance of an aircraft caused by flapping motion, the system comprising:

The motion capture system is used to collect the motion signal of the flapping aircraft and upload it to the upper computer;

The upper computer is used to receive the collected motion signals and attitude signals of the flapping aircraft, analyze the signal characteristics of them respectively to obtain the corresponding spectrograms, and determine the flapping motion of the aircraft as the source of attitude disturbance by comparing the spectrograms; receive the throttle signals and flapping wings. The motion signal of the aircraft when the throttle signal is gradually increased, the signal characteristics are analyzed, and the throttle and flapping frequencies are fitted; according to the fitting relationship between the throttle and the flapping frequency, the flapping frequency corresponding to the maximum throttle signal is obtained, Use it as a frequency threshold to design an analog low-pass filter to filter out high-frequency interference signals; perform spectrum analysis on the low-pass filtered signal after filtering out high-frequency interference signals, and filter out the main frequencies as the disturbance signal frequency design simulation according to the amplitude threshold Band-stop filter to filter out disturbance signals;

A flapping aircraft control system, installed at a position close to the nose of the flapping aircraft, includes a controller, the controller is respectively connected with a sensor, a digital low-pass filter and a digital band-stop filter for controlling the flight of the flapping aircraft, the The sensor is used to collect the attitude signal and upload it to the host computer. The digital low-pass filter is transformed according to the analog low-pass filter designed by the host computer to filter out high-frequency interference signals; the digital band-stop filter is designed according to the host computer. The analog band-stop filter transformation is obtained to filter out the perturbation signal of the flapping-wing aircraft.

Example 2:

The purpose of this embodiment 2 is to provide a method for filtering out the attitude disturbance of the aircraft caused by flapping motion.

In order to achieve the above object, the present invention adopts the following technical scheme:

As shown in Figure 9,

A method for filtering out the attitude disturbance of an aircraft caused by flapping motion, the method is implemented in a host computer, and the specific steps include:

Step (1): Receive the collected flapping aircraft motion signal and attitude signal, respectively carry out signal characteristic analysis on it to obtain a corresponding spectrogram, and determine that the flapping motion of the aircraft is the source of attitude disturbance by comparing the spectrograms;

Step (2): receive the throttle signal and the corresponding motion signal of the flapping aircraft when the throttle signal gradually increases, analyze the signal characteristics thereof, and perform the fitting of the throttle and the flapping frequency;

Step (3): obtain the flapping frequency corresponding to the maximum throttle signal according to the fitting relationship between the throttle and the flapping frequency, and use it as a frequency threshold to carry out low-pass filtering to filter out high-frequency interference signals;

Step (4): Perform spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal, and filter out the main frequency as the frequency of the disturbance signal according to the amplitude threshold, and perform band-stop filtering to filter out the disturbance signal.

The purpose of this embodiment 2 also includes providing a computer-readable storage medium.

In order to achieve the above object, the present invention adopts the following technical scheme:

A computer-readable storage medium in which a plurality of instructions are stored, and the instructions are adapted to be loaded by a processor of a terminal device and perform the following processes:

Step (1): Receive the collected flapping aircraft motion signal and attitude signal, respectively carry out signal characteristic analysis on it to obtain a corresponding spectrogram, and determine that the flapping motion of the aircraft is the source of attitude disturbance by comparing the spectrograms;

Step (2): receive the throttle signal and the corresponding motion signal of the flapping aircraft when the throttle signal gradually increases, analyze the signal characteristics thereof, and perform the fitting of the throttle and the flapping frequency;

Step (3): obtain the flapping frequency corresponding to the maximum throttle signal according to the fitting relationship between the throttle and the flapping frequency, and use it as a frequency threshold to carry out low-pass filtering to filter out high-frequency interference signals;

Step (4): Perform spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal, and filter out the main frequency as the frequency of the disturbance signal according to the amplitude threshold, and perform band-stop filtering to filter out the disturbance signal.

The purpose of this embodiment 2 also includes providing a terminal device.

In order to achieve the above object, the present invention adopts the following technical scheme:

A terminal device includes a processor and a computer-readable storage medium, where the processor is used to implement various instructions; the computer-readable storage medium is used to store a plurality of instructions, the instructions are suitable for being loaded by the processor and performing the following processing:

Step (1): Receive the collected flapping aircraft motion signal and attitude signal, respectively carry out signal characteristic analysis on it to obtain a corresponding spectrogram, and determine that the flapping motion of the aircraft is the source of attitude disturbance by comparing the spectrograms;

Step (2): receive the throttle signal and the corresponding motion signal of the flapping aircraft when the throttle signal gradually increases, analyze the signal characteristics thereof, and perform the fitting of the throttle and the flapping frequency;

Step (3): obtain the flapping frequency corresponding to the maximum throttle signal according to the fitting relationship between the throttle and the flapping frequency, and use it as a frequency threshold to carry out low-pass filtering to filter out high-frequency interference signals;

Step (4): Perform spectrum analysis on the low-pass filtered signal after filtering out the high-frequency interference signal, and filter out the main frequency as the frequency of the disturbance signal according to the amplitude threshold, and perform band-stop filtering to filter out the disturbance signal.

These computer-executable instructions, when executed in a device, cause the device to perform the methods or processes described in accordance with various embodiments in this disclosure.

In this embodiment, the computer program product may comprise a computer-readable storage medium having computer-readable program instructions loaded thereon for carrying out various aspects of the present disclosure. A computer-readable storage medium may be a tangible device that can hold and store instructions for use by the instruction execution device. The computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (non-exhaustive list) of computer readable storage media include: portable computer disks, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM) or flash memory), static random access memory (SRAM), portable compact disk read only memory (CD-ROM), digital versatile disk (DVD), memory sticks, floppy disks, mechanically coded devices, such as printers with instructions stored thereon Hole cards or raised structures in grooves, and any suitable combination of the above. Computer-readable storage media, as used herein, are not to be construed as transient signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (eg, light pulses through fiber optic cables), or through electrical wires transmitted electrical signals.

The computer readable program instructions described herein can be downloaded to various computing/processing devices from a computer readable storage medium, or to an external computer or external storage device over a network, eg, the Internet, a local area network, a wide area network, and/or a wireless network. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer-readable program instructions from a network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in each computing/processing device .

Computer program instructions for carrying out operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or in one or more programming languages Source or object code written in any combination of programming languages, including object-oriented programming languages, such as C++, etc., and conventional procedural programming languages, such as the "C" language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer, or entirely on the remote computer or server implement. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (eg, using an Internet service provider through the Internet connect). In some embodiments, custom electronic circuits, such as programmable logic circuits, field programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), can be personalized by utilizing state information of computer readable program instructions. Computer readable program instructions are executed to implement various aspects of the present disclosure.

It should be noted that although several modules or sub-modules of the apparatus are mentioned in the detailed description above, this division is merely exemplary and not mandatory. Indeed, in accordance with embodiments of the present disclosure, the features and functions of two or more modules described above may be embodied in one module. Conversely, the features and functions of one module described above can be further divided into multiple modules to be embodied.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A method for filtering out aircraft attitude disturbance caused by flapping wing motion is characterized by comprising the following specific steps:

the motion capture system collects a motion signal of the flapping wing aircraft, a sensor in the aircraft control system collects an attitude signal, the attitude signal is uploaded to an upper computer respectively, the upper computer carries out signal characteristic analysis on the motion signal and the attitude signal respectively to obtain corresponding frequency spectrograms, and the flapping wing motion of the aircraft is determined to be an attitude disturbance source by comparing the frequency spectrograms;

the step-by-step fixed flapping wing aircraft throttle motion capture system acquires corresponding motion signals of the flapping wing aircraft when throttle signals are gradually increased and uploads the motion signals to the upper computer, the upper computer analyzes the signal characteristics of the motion signals, and reads throttle data in a log of the flapping wing aircraft to fit the frequency of a throttle and a flapping wing;

the upper computer obtains the flapping wing frequency corresponding to the maximum throttle signal according to the fitting relation between the throttle and the flapping wing frequency, and the flapping wing frequency is used as a frequency threshold value to design an analog low-pass filter, is converted into a digital low-pass filter and is arranged in an aircraft control system to filter high-frequency interference signals of the flapping wing aircraft;

and the upper computer performs spectrum analysis on the low-pass filtering signal after the high-frequency interference signal is filtered, screens out the main frequency as the frequency of the disturbance signal according to an amplitude threshold value, designs an analog band elimination filter, and converts the main frequency into a digital band elimination filter which is arranged in an aircraft control system to filter the disturbance signal of the flapping-wing aircraft.

2. A method according to claim 1, wherein in the method the aircraft control system stores the collected attitude signals and throttle signals in a log and the upper computer reads the attitude signals and throttle signals in the log.

3. The method of claim 1, wherein in the method, the upper computer performs signal characteristic analysis on the motion signal and the attitude signal respectively by using FFT to obtain corresponding spectrograms.

4. A method as claimed in claim 1, characterized in that in the method the analog low-pass filter is converted into a digital low-pass filter by means of a bilinear transformation.

5. A method according to claim 1, characterized in that in the method the analog band stop filter is converted into a digital band stop filter by a bilinear conversion method.

6. The method of claim 1, wherein in the method, the method of screening for dominant frequencies further comprises:

sampling the low-pass filtering signal after filtering the high-frequency interference signal by a specific length, carrying out zero filling by adopting a laminated retention method, carrying out FFT (fast Fourier transform) conversion, and screening out the main frequency according to an amplitude threshold value.

7. An attitude disturbance filtering system for an aircraft caused by flapping motion, the system being based on the method of any one of claims 1-6, comprising:

the motion capture system is used for acquiring motion signals of the flapping wing aircraft and uploading the motion signals to the upper computer;

the upper computer is used for receiving the collected flapping wing aircraft motion signals and attitude signals, respectively carrying out signal characteristic analysis on the signals to obtain corresponding frequency spectrograms, and determining that the flapping wing motion of the aircraft is an attitude disturbance source by comparing the frequency spectrograms; receiving an accelerator signal and a corresponding motion signal of the flapping wing aircraft when the accelerator signal is gradually increased, carrying out signal characteristic analysis on the signals, and fitting the frequency of the accelerator and the frequency of the flapping wing; obtaining the flapping wing frequency corresponding to the maximum throttle signal according to the fitting relation between the throttle and the flapping wing frequency, and designing an analog low-pass filter by using the flapping wing frequency as a frequency threshold value to filter out high-frequency interference signals; performing spectrum analysis on the low-pass filtering signal after the high-frequency interference signal is filtered, and screening out a main frequency as a disturbing signal frequency according to an amplitude threshold value to design an analog band elimination filter to filter the disturbing signal;

the flapping wing aircraft control system comprises a controller, wherein the controller is respectively connected with a sensor, a digital low-pass filter and a digital band elimination filter and is used for controlling the flapping wing aircraft to fly, the sensor is used for acquiring attitude signals and uploading the attitude signals to an upper computer, and the digital low-pass filter is converted according to an analog low-pass filter designed by the upper computer to filter high-frequency interference signals; the digital band elimination filter is obtained by converting an analog band elimination filter designed by an upper computer so as to filter disturbance signals of the flapping wing air vehicle.

8. A method for filtering out aircraft attitude disturbance caused by flapping wing motion is realized in an upper computer and is characterized by comprising the following specific steps:

receiving collected flapping wing aircraft motion signals and attitude signals, respectively carrying out signal characteristic analysis on the signals to obtain corresponding spectrograms, and determining that the aircraft flapping wing motion is an attitude disturbance source by comparing the spectrograms;

receiving an accelerator signal and a corresponding motion signal of the flapping wing aircraft when the accelerator signal is gradually increased, carrying out signal characteristic analysis on the signals, and fitting the frequency of the accelerator and the frequency of the flapping wing;

obtaining the flapping wing frequency corresponding to the maximum throttle signal according to the fitting relation between the throttle and the flapping wing frequency, and performing low-pass filtering by taking the flapping wing frequency as a frequency threshold value to filter out a high-frequency interference signal;

and performing spectrum analysis on the low-pass filtering signal after the high-frequency interference signal is filtered, and screening out the main frequency as the frequency of the disturbance signal according to an amplitude threshold value to perform band elimination filtering so as to filter the disturbance signal.

9. A computer-readable storage medium having stored thereon a plurality of instructions, characterized in that said instructions are adapted to be loaded by a processor of a terminal device and to perform the method according to claim 8.

10. A terminal device comprising a processor and a computer readable storage medium, the processor being configured to implement instructions; a computer-readable storage medium storing a plurality of instructions for performing the method of claim 8.